Siemens SINUMERIK Series Function Manual page 538

N3: Software cams, position switching cycles - only 840D sl
8.2 Cam signals and cam positions
Figure 8-3
The signal change of the minus cam makes it possible to detect traversal of the cam even if
the cam range is set so small that the PLC cannot detect it reliably.
Both cam signals can be output to the PLC and to the NCK I/Os. Separate output of the plus
and minus cam signals makes it easy to detect whether the axis is within or outside the plus
or minus cam range.
If this condition (plus cam - minus cam < 180 degrees) is not fulfilled or if the minus cam is
set to a greater value than the plus cam, then the response of the plus cam signal is
inverted. The response of the minus cam signal remains unchanged.
538
Software cams for modulo rotary axis (plus cam - minus cam < 180 degrees)
Function Manual, 03/2013, 6FC5397-1BP40-3BA1
Extended Functions